SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad9a2bc1a0bdaffa6845cc625236f55321b064a1e77a5415f05ae7ea60019ae0' 
  AND token = 'lx3eii816pRS2KjwpCuSH5uAWqcY1bGvqq7+FlJioT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}