SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f305d7cf6b52e307205a71d36acc7c11d0199d7b742b4805c4df28c39f753b' 
  AND token = 'YAfURGjPjUSiBb7doo0sP5G1kWBHE5P8l+mW05F5zmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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