SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd815a8f2039c3629e9ebf30c8e2a74585bc8209004db63a16d245ed141583918' 
  AND token = 'NhqPg0uvGEhjpETwwJ6WcFEAVJyWgDN596y46sdZ+J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}