SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eded6091585ac5587dd8fac6548545e9853f9526733ab71d53c0c0cc79829b7' 
  AND token = 'zuDjejtwleRUAKtuBEd/8CIwIY56DsD/ftTpgTNTu5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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