SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64203ab4695fb5f87fc4c6f7baf9761602af6e5c389d745b95e8add3bc3e0a29' 
  AND token = 'oEElz2nNAZmqSw/Es22j0qe1jzLjtUyFFTKoHtkp+OY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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