SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bae249818eda9dc57491312c24e7510e793556f329baf1a3fe0e6be82f0b001d' 
  AND token = 'RiXkrFN16ZiaFoer5zyeZPAsX7FmXE6NnjXJovttCQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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