SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba178125b0ab1e83fcd594bb6c57e6220bc99c03c3f6e01722f36b6acfad67ad' 
  AND token = 'RUfLPYpAsrAGlPr/XBGfIK0iV2LVS8uvXubmQWP4Zz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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