SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2bbcd6deaedad04606873693c1835aad855a0b93bec373d2cbdcaebdc27b809' 
  AND token = '7PJjljR9qhoXg4dSujUiPgDtFyqGvmV7rMdeTcYsoDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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