SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9dbb8d493a81c04f3655fc48c002166a694ea4a27322f73d0e40f8c05094b54' 
  AND token = 'OVzg3Tbq4M1Xg7DG1kweooUFUwBY1avJjOIqOif/pNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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