SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bb00e1fdcbf4c7d40146f4c964bc5ea420f7256295bcd4da23600022720bd34' 
  AND token = 'qdRxuYpprYu6lG/qtxjnTwpVik0/cKmp9v0Cg+NJjj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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