SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e172211f69c67eb169b0f320340937487090349bc8095f003fbb4bf7f2e6227' 
  AND token = 'C8IhkNhqunsLJNvGQ2VT0Cm12WnS1Gb/SmkIiUOOuJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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