SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca73f7bdaf56708c6938761cc03e9749aa4d6514a55e916d1c3296f5493dc74' 
  AND token = 'wb//l7+/AFwrz8nzEFDIiGORbyIUsKYbRIK1aYWL44Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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