SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb2ec52b7660de0f7abb6cef354066f5ccaab3eaeb973628ebca401e6c64795' 
  AND token = 'c64KEhtSnlahKw5yKssMapYfXjtDmNYVFkmpdMLmR6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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