SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a54634b7bd6162cea34e893ba16a45935dd651a3bdad1de7e062b37316168e34' 
  AND token = 'kbKxdBQIk1Mk514OXMN9tpVq322H5gTIQdtZTjQruXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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