SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdfc4be0f635fd2a100c4ea580c347ff7aea19c75db887a0f50fbf3d6699dd12' 
  AND token = 'J4dCJYsbu6N8QPch49dzbKKqPUMsYlIxExmXI+QL7wY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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