SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df165848c84b3f3a5f24a331dfa769a1eac5e272ddcc61e55f8534a84e478ff' 
  AND token = 'sAOGBlc38P0Fah15HmXFgj9Eac5/ZeBmMz4sIlBQGtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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