SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3de5eddf93919b1ebde073b2aaf7e83a59bbc24350de919d61ecad85359cf8f' 
  AND token = '7i3KmPXvbzDCllEQzbwNh2zI1wJ9LPfnZYAIKsnElqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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