SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58a449553f58ad08fd704107d571a61f19e521e4deebe6f8bfc664e4a8584dd' 
  AND token = 'n02ojymxmzH+RvKP9G8x7XCLODiIhkmlTBI7u3/w4q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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