SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f86eb783978269b45a4271682dacf149544f07a94e8c5b33725bf219e454821' 
  AND token = 'aLq0Jkyt8UVQ6RE6BBWAuQ/upov5Kohc0qhoGOm3Ag4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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