SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '379028264cdc3c85ab3ea7ef3ab712f3d4bf03aababff1b6a4e302ca6c9bfd14' 
  AND token = 'nk9Ps416rQ6jzl83xhOARKYQmoVMRq8hdfBY88SHc6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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