SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8cfe831f5b1956890175bfc3daf3782ffff75cea557d3a230b8c0efee81e73b8' 
  AND token = 'm12EaWYTztGz9uvq5nK7IyAP3+f6J4c4zqsV0de4jCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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