SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9d524c5640c66e02638855e7044cafeaa22e6717b12af7e11eb6d5097e55c0e' 
  AND token = 'hSNv4WGf5Wu1u4NhrMYkWHiUOa0bajlMBZvofmyqGq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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