SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7350bc2f8995f24161c78179170086ec9629de1d8ef4634df783042da15f358f' 
  AND token = '9a2AhL6/RJezqm4VqLaupFXk3zBprq61ZEsvx4mbsr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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