SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8b81b6b5ef1a7481722f98244e46fa3611858c81498f54f8ed39a0e945189d0' 
  AND token = 'HGgNZLZYdl3WTy4uzOO6jJQhJAkDKOjuA3mIFGlOJjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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