SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39bdafc113504bb629812f6e7b201e33892bc4768ed4795515a5bea0179164d6' 
  AND token = '/lnhbXrOCAh7EGnmVDb6gjVSJDs/HUSjQZqrlTbVFJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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