SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd743d5f8d718d7fb2f65f0fba8de8e2449b23fe37c7174975ad0f5b1b95146e2' 
  AND token = 'NkRrnFs+TtWfzsZqhzzcuLt5K8+HKztc1J1nPBPdzvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}