SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4f952a7400e2f5e48ed3783aa6ddbb41e0b37f32b6420682920e885da08341b' 
  AND token = 'YQS0QqwZO/uk/nHKBzkxNoXs+MB2OeVzex/IWXxdlmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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