SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95f6bad3230b35a081ab33ab482a29e26149d3016ab77313d29510168374fd11' 
  AND token = 'SKQoVgiyfH0ATOsRZXfZlXKMWawHeS1s9Yla59alUQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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