SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b99bd4327a45f49dbaf9802f23e4cb46b8db9aac852f810d04dd3c4496db14f' 
  AND token = 'M6T6fkp9LqtrQVP1aJnPdc+TncWsuX+CwSBrF3R3uoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}