SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45da903c4d44d3957bd2c362f935a5084641d6ce22ff28015a9adc0315ca188a' 
  AND token = '4h6VVxTCGzwERsqRR955p0ja3BK5tyFnZYQ4A+wBmFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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