SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ceacd8d5dfa45037e475c259da5c206abaf2ed033c91647a44733d967c934175' 
  AND token = 'k+jVDJqvb0/OnI2+ynNt9fm3HzuX05BBaHCyiPAYmsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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