SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc8f80610dd7b410655da81ce37da0be498e773a22000ae2262a2c9955a0c8ee' 
  AND token = 'bsCYtggzyygxwvM0MuqqXJepnWZCqzPsS8e9hEC+hXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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