SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '54b12a8a47890010a8a23a937db9329ef263c0d7b47c1c47038e88f3e0932f33' 
  AND token = '+iOR8QVe+kEvVLgR7Ou5AypyiJ4PIQQ6HQv5to9O+JY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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