SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc2a7b6848c3c9941803db8dbb68812fbaa9eed41005c9aa480d5b30e4e4f3bf' 
  AND token = 'ICoUqFu33/vxzRodkHAcZt1WZGDf++eVwCcfIbL9S1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}