SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a66c3b9280a1847151e92f6e5e3b22ffb15a6adafb1c88953ddc428634af133' 
  AND token = '9M71FCmBgyyWZcnLoQvAZwlrlwZnidvJMImfTLA+5d4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}