SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b6b95a920fdc927b3fa3935e47b04fce2aff2c750279318ce936c81b51c3c89' 
  AND token = '1EZeKlNEu2I6gv8HuMFlZHRTlSIJzQVudFwOYqpR10w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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