SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '141c4785844c86167718d631ffc9e1536f5cb61f0d60da1ffebbe08028f9487b' 
  AND token = 'IliDKNQBcxY//0/RQHeHzO5JGEx7pZfVmw0LVCfl8wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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