SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c401eea2f102ca1e4589c512625529dc1853863518763871c7df955c61b1b65b' 
  AND token = '/3kqURb0zkP7GsEyTHGiFbMTvnMI/4ZrijA23kurBpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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