SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'feccd533b118dfbf7f8bcab3737854d08643497e4c3ecaeb27d1ebc9054e8b7b' 
  AND token = 'YpUPLuDBmT2E8cFxZXNoUOpf75ifkBP/JdHe+uA12X8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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