SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37af9b5f9926feb5c545b3fd47ace038734aa88c5f3b96f0399fbc20e2da3185' 
  AND token = 'nc2/H7mEJMMDEqSwgsSZlnD2uurMrTT8DkiHvqv61kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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