SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '474392ac9d63bd805be750972e0428451f48ae41f825e44890321df2e193bc24' 
  AND token = 'DdwgjDBBM4Ws0SVpTLOj8Y2kJAQkaNlQCA02DuneCFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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