SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '68eabe6837a2794fb22f82a63d026ed1c02e0f63486c6841244ceda32530734c' 
  AND token = 'nUkndP+EhpYNB5ZPeViSruKhsJZT1Tpd6w7c2dEZYRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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