SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61169c64a8cd13c3b5aeadaf14162757d2f94944a738d1dbadf2e8733bbb7be3' 
  AND token = 'vYurNvQAOBHs+VpLAJuYzmoyk/Uq8A0qmiWlG27Uxfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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