SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c336f1d87b6187a7bc0627ac993b4709e269d38583c059b01b14524cf0c7537a' 
  AND token = '7Q1kVDKNoA72aSRLhGQi8I1hsmzlh6RgM/UjUAJBVCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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