SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edfc6ebd95045ffdd43be137a936d2db9d941ae19b7de4b32507bd76a6fd702a' 
  AND token = 'P8EtoXstRxhCxfZT2Is/TCE7PGinJnFCB6FNoiprWgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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