SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd00df8d5ad8f55471eab09cf92898499e2ce92605c48357a71c2a1ae52ed5f27' 
  AND token = 'BwTckEoOf71UEVsRfCD7nmhM0b+k/JCGypzSh4FbDYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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