SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de072b430cf774ed19f0c1ce78f4250bf70d7d095b0a41e66d6164bb4cdaa04a' 
  AND token = 'jWt3oWAHdiGA90uZBNvO19O/uNmr803+ewUAgLecqYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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