SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bfab3fc026df0e6ac627e659dd3266bdadee102ae06bfd1766490a5dea6b76a' 
  AND token = 'er9/v7IZXrNllFl8gMFP1djPowY3x07yaf37+JtLrwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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