SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c4b4dd906a548f59c9734d3435d4a839f51b01070bf987415b4512efa35caf3' 
  AND token = 'WCQUY+cTTLS0fqDY6oKWR3CmnrrjWFLqMrJoE5N5yTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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