SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e446e4a9e5ec556f9cc70e4533b44568221eb0c4af99a0719628378f457a48f8' 
  AND token = 'G9g2wCTLuflCQllwpAXegdXjnu0Zv8t1fdltQbA0Cns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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