SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77fec75780c2f641c6c95be518a78b34419d7b00b28af0bf9b00b5ca7788e74e' 
  AND token = 'lyT/3JhVYCcsrTj3dap6+Upww/Iq7FG9u0KUmziPXMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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