SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d8544288633d6b21ea066201cbfbd6d80208e687164c85331b9835bd20274fb' 
  AND token = 'P9RPqX7+iQszjbdw6Ti/x9wUwF/0PMt64ZIKylSYB4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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