SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78a6f49f3c9fa16ba76ebd095cdbbf91b34f4a218395cfbc81fa3991ddef225c' 
  AND token = '9tZkJywHaV2NBtzABMSCaETdkiHDfE71FGf02uYfXfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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