SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd58a44b76ff24837b33e639c1c4cf9a53f3ee95fcfaf385877a6b8975f6235bd' 
  AND token = 'HA1PwBIYL/d5Q8HHvzBWVqMeAUOjKUjaFs5tAnApPr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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