SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3416ff1fc8ff450ec3f6857e4b6ba072bbc85d96cf29256bef40647c03ac8e39' 
  AND token = 'jfDFAt/MjPEjjmPOn1WhSQLWKB+ZJ8Z4PRDgedh4/cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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