SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c29629219fd15197f285a9301aece8489d4d1ac55380895b83167e3d898156d0' 
  AND token = 'mTLt9NESInmkzAFcCr8Z/aV9fUUa1/DvDABvU9AXs2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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