SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8726062f3fdb7996bedd920be1a195d72130fbf3eebbf30e81e6a27508a03349' 
  AND token = 'r/6fjgupQzZ64ZjL5UzimQkRP1EkYw+JlEC8Fgt+oqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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