SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4464b401c4df6939905418d8a3aef512801c186d9322160b5522d672980bcf10' 
  AND token = 'OoMcjQmZ4idTpZYThuxpRwkYtAmYcVbuBZduvOLGw0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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