SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf5acbd1721e272e0a090f8ae057a7503d23c75dcfb03705043c815539a44c6' 
  AND token = 'G4Bf/t/7oQZGq/G1YZKeEfN81kjfDVUsSVqFB/J1IiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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