SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '305eee83b113fd7a14ae5bd0dd401e560ed85cc9911a3d49daadd259c31fcd6e' 
  AND token = '8IajgPUEP25/bNhURDOL992ZXhSpBSZPFiNxopQxpTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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