SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435968eaa28dcbbe2aa1b349ff8d8b84889c4527a112d54bdab38a1412447d11' 
  AND token = 'yysqwHUSmlydpUmW6belZcnEFnTrOGgYJWq2IQ85S9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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