SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49da0f6364ec36d636cbd0d833ff7eb5bac1374890245f79f7bee3f3ee831b32' 
  AND token = 'AiORXnd+XXXxlpWVSEEWbRb1ieaiBUrTJEJVrdJGxM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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