SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6752541c88b0ce460500d21605ac1c0ec3ae94bca3bf9427d33891dca5a67784' 
  AND token = 'WC8zeyJu4VIfA6iFk6JOLzPW0jTFZLFEmt49aZ6scJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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