SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f75e2da204184933214102f303c5133f5656117694ac5a0cf688dd00cde4fee' 
  AND token = 'OK23Z6/C8ldhBukfHMzDPY1c9c2sv7rGzL9PK7Nbg8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}