SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fe1e3a1ae9483751a440c659d9cc0180c3834f4dd0e9a16fe57a0dd7323c0b8' 
  AND token = 'bSikIreuMryUC5nB/2FwOo6A4LKC1JOyq0Afe57u8ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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