SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12187d3c7b8a09dfdb73ca5fc9a7829bf554aca5d2a6957112164f39afa2172d' 
  AND token = '1yJVn8IdNNJPwIoELTPnNDliDkucQhzK3DQMbyy49FY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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