SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '749991711b84812cef562a165c01e4f66d207864895132b9470b7527b1a14bc5' 
  AND token = 'v+ACWEniPkJYRcjXhFwZ+eEVixsU66SpyBC0jY1GOOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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