SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7a78ddc5fa2c1824f88d2f402958342457c379c60853615b97928d7dc889258' 
  AND token = 'CAZrxh3XPUjts+LDEOHJV1ctR7H9z6jq6wo0dT+oB8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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