SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a145de592442284d1613bfb740100988a4b2680f88fd415eb56bbbbf2388eccf' 
  AND token = 'EQkx5G4qblFys0JThSreeuT8+VqLZaAZROhSJwOP2FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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