SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da79b874ed7e8102610d9440501c846ac6554cf5ddf83cdffba18a09a316e574' 
  AND token = 'mfRDPW2Ll91whRiVZX6PK2qJaOzh+Gf8c+j/mhuxmhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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