SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb95bf355b85cb6ef5f4a7d952c0c532d8d03ea8b633601481651a8abe180435' 
  AND token = 'xTx03TBsNZPawyORplUWKyGLZronVEw6g43r65R/ZjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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