SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '70fd4be8739bc612b59edf31b4712ad80125c14d550de4df6769a0ec1c923474' 
  AND token = 'olOMt6fHvzNNKoQUgnwpkENJKvzVZU53JlxV9qCS3S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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