SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08fc44d2b2ea0940ca9fb77eed6dd8561a8d70125522b43101fbb3f7d3ead0ae' 
  AND token = 'nEJFOWVAK8gs/Hs2zxIm5Qg3q8g83hNWKJ7jxGtz/Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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