SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa621d95656f5af529ea3174b2dade0fba39c3595a0d1dbd6b7b4fb50dac312b' 
  AND token = 'u8lphtcGmU9Z3VZKl2QVP8JDj5f5GPTi+m+eFXBD22g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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