SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e5bfd825a4be7efbf982c987907c7f5ce37f316f9e4e5062b94b97b02062ddc' 
  AND token = 'YiMvcWVqGRt7pIJAcwayNrgtaydfvfSgQXX+6GWsf4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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