SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fdaf9b7058c2c57411c38d0313356c7350ace8b561ff2733fd28e037028c6b9' 
  AND token = '2eEwUEnQoIVKPDSX4LKsXVMBkAFLmWskU2GeP8wYB2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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