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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a37278774673bd5aa3131c6e1f7e8b792279cd49ddcd6dd8ed733ee499ba6ae9' 
  AND token = 'MPFpt7mjCiKr3m4eHHd4KEz3F7uoGtFByfmLheWKYg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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