SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8cebdada1373bd1740b26ef1576744e578a4ee6af04eaabd49907c6a43764f0' 
  AND token = 'hSy75ci8YFbRO7Op5lSw8LUnAtpoCgJMfnWYuki4Bf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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