SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f018db9ca6a253e7c29a32835c2602b60eb137c8023c6ee0349a025d85a7072' 
  AND token = 'DKVKKR5nVMTMYPyeYgjMAsXp8y806835rLduKOll7e0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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