SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fae768ba7b44952ecd3d57d2fcda8db1e19ae51313d591618a3c5fc6a37c6ab1' 
  AND token = '2+yjyphhyhUZ7va/3bZuLLKWU02XcpMY1h/cQ6m12Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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