SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e1abe2a8c4a819f6d6ee56f2daadcc18af69cfab41fa595fc92110027790a17' 
  AND token = 'mPYA0Adf9hjyDD4qqb8/JUWVGrb/x/3PdSOqV+4OlbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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