SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d4cac6f845a7df693128d35638f56c0bb948fc253430e16dba6cb973392e1bc' 
  AND token = 'eg/RsajjwwTpxq+TDYXDM1HjRfvycNqJNVX6wCqJrQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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