SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2395fd53d2a681436ef8014f1edc4911fdc96caf0534f92a33ebf795b82b394' 
  AND token = 'ibj/Meiz56NCwG6gVMNBhUoOTVzhZ2FdzUcYGJmyayg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00103

JSON explain

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