SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc34ef76267cd755d5da89e00c9dbee758d26091374ebd4981361c7a3a342022' 
  AND token = '+K/KUKmj0gBwymD4pUShPrypEq55VZcn6ju/6Y2IrD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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