SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7e5aa10b344c1278e2fcfb2dd37c3cc9d14aa33290d03a449f9768c73689b55' 
  AND token = 'nWTqzY8Ieq1owvz8SRGwlqLt8gfcQjqL1hQelCxBaCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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