SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2da7e852fac535d91a86fcc9d685f217a9731bbb23e617567aa1f68da4eabc28' 
  AND token = 'AA0/2iylMmaAVJeKBGL5XSimKvDMhcoVqdoGUpQXow8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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