SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd24bc9d0d5f046bad06eee5c02c0a0ffe4dbde8f0b9bbe76aebb039cb0c18bfa' 
  AND token = 'M3pBaAe2pCBCVs8N7zjj3nsuc60jjmKeL14kSfeFEiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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