SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a85b8432816992f9881c24fce106b4cae870293d5ac3849dedcd77e297fbd9f' 
  AND token = 'HlsbyR0vJrdXWBh95FU8e350bnRJes9P7XSycrTIcXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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