SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ad99289fc239c5f01e5d9cd8286cb664d6fbc2b2231e1778b4e524749a5ba974' 
  AND token = 'MIMYyicO+23FYGEerkztrQ6u65WceAXnyxHg2hx6/pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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