SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '37ba3a79f84d7310771e71158bb5d003f0ff38752a164dfcdfc48c4a2e4e5ba4' 
  AND token = 'tyWdEuSdJrlkBUVvfthuMQXqG9d0RwO+Wmv5+zpPeNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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