SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '958118112fbfa14d124a4ef603abcbe542ebf31a4eb75e91252d6795726fbc72' 
  AND token = 'mwwHf9bjyyPlmGnA5EgJpR7eaMyYcZHjgrBJCDgG+Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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