SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73e51eadc944e4fe5a5652ce6c5c7fee987abd07fc7e1967b6f463625dc202b3' 
  AND token = 'zl9xZKgh1Lv8yr0JOMVFDpCOElTcgqzpkS2bFUQ+h7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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