SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '186278ee3bf2a9a534198a617688dd4f30062f6ddf58a704b72e95bb2b9c07c7' 
  AND token = 'rQ1nJsF+6KVpCyrQ6vhgunVmFthvE0nS0rS+5z9Vnbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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