SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7301b7967c835b02cafc8aee7a3f30742947ebb270e759251337f25984ca415f' 
  AND token = 'iahYvKPxcf1Vj88D9yar2PisbRsaCuMYQCZ6KagCZFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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