SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8c2b79acdae5b4c112f94eeb5dd1b9f9312ddec4b705583da1601c0e8cc7704' 
  AND token = '3Ah4XrJiU0HNj8KeEjiph6jtiKvBxNnUZp51lWS+0Lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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