SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a04ee9fe1051bbc79129c84fa07220e4266f6b904545cd5d53156e3eb631039' 
  AND token = 'Pn+0Y1jVpsaTkCdUHzrXLKwgm7R8NuoKlqDRQDhZW+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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