SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8ae48b5bf6a111cfa4b552052a5b071da57a2afd054981a6e9377253617d000' 
  AND token = 'p6ryrWD/dOpMx4FDyqN4SEnkjfCSgrKOfgzzXb83az0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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