SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b71d3a1a38ef60c37d6ecd75bd3c3b18af3ba46010ee720429748db68d4e77' 
  AND token = 'ABdMvV7Dtc7b/c6RMtslHc4uBPD/M8DO0x7bS+fdqrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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